In electronic systems such as power supplies, motor controllers, and electrical distribution networks, high voltage power transistors are used in high current paths to switch currents. Recent improvements in semiconductor device technology has allowed for high power transistors that switch faster and dissipate less power during operation. Two common power transistor types are the metal-oxide semiconductor field-effect transistor (MOSFET), and the integrated gate bipolar transistor (IGBT). While both transistor types can be manufactured to handle large amounts of current, care must be taken in operating the transistors to avoid destruction of the device during normal operation and during electrostatic discharge (ESD) events. As such, power MOSFETs and IGBTs are commonly driven using specialized gate driver circuits that manages the gate voltage of the MOSFET or IGBT in order to prevent over-voltage of the gate and/or latch up of the device.
In very high power applications, such as those used in hybrid cars and electric vehicles, a further gate boosting stage may be disposed between a gate driver circuit and the power transistor in order to provide enough power quickly drive the input capacitance of the switch. In some cases, the boosting stage may provide about 10 A in order to activate a corresponding switching device to handle 500 A or greater. Because hybrid and electric vehicles have very high safety standards, device protection, fault detection and redundant circuits are often employed to prevent system destruction and to ensure safe and reliable performance in a variety of different environments.